# verifyOffChain

### Description

The `verifyOffChain` static method verifies an off-chain ZPass proof locally without accessing the blockchain.

### Parameters

* **`options` (VerifyOffChainOptions)**: An object containing:
  * **`execution` (string)**: The execution trace to verify, output of `proveOffChain`
  * **`program` (string)**: The Aleo program source code
  * **`functionName` (string)**: Name of the function that was executed
  * **`inputs` (string\[], optional)**: Array of input parameters used, must be provided if `verifyingKey` is not provided
  * **`verifyingKey` (string, optional)**: The verifying key for the proof, must be provided if `inputs` is not provided
  * **`url` (string, optional)**: Custom API endpoint URL, for keys synthesizing purpose

### Returns

Returns a Promise that resolves to a boolean indicating whether the proof is valid.

### Example

```javascript
const isValid = await ZPass.verifyOffChain({
    execution: executionTrace,
    program: programSource,
    functionName: "verify_credential",
    verifyingKey: verifyingKey,
});
```

### Notes

Either `inputs` or `verifyingKey` must be provided. If both are provided, `verifyingKey` takes precedence.

If `verifyingKey` is not provided, the SDK will synthesize the verifying key from the inputs and the program.

Synthesizing the verifying key is a computationally expensive operation, so it is recommended to provide the verifying key if possible.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://zpass.docs.aleo.org/zpass-sdk/overview/verifyoffchain.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.